Method of producing bearings



July 27, 1937. E. SEMMLER METHOD OF PRODUCING BEARINGS Filed March 7, 1935 8mm '12 l lNvew-tow Patented July 2-7, 1937 UNITED STATES iun'rnon or? PRODUCING BEARINGS Erich Semmlcr, Berlin-berschoneweide,

' Germany Application March 7, 1935, Serial-No. 9,885 In Germany February 6, 1934 4 Claims. (c1.'2 9 149.5)

This invention relates toan improved method cially for aeroplane, engines. 8 Recently such bearings have been constructed with a shell of steel lined with an alloy of copper and lead, the intention being that the steel' 10 quired of a good bearing.

For this purpose alloys comprising from 80 to 60 parts of copper and from to 40 parts of lead are employed, but, as these alloys show in the course of manufacture a strong tendency to liquation, i. e., for concentration of the lead to take place at certain parts,' their serviceability is thereby greatly reduced, if not completely destroyed.

To prevent these local concentrations of lead 20 the bearing must be chilled abruptly'im'mediately after lining with the lead-copper alloy, but this chilling hardens the steel of .which the bearing pleted bearing, in certain circumstances, an undesirable brittleness which reduces its durabil ity or makes it quite unsuitable for use with engines which have high demands put uponthem.

To avoid the difliculties which arise due to the hardening of the steel, used for the bearing shells icon and the manganese may not be present in the composition and,

0. carbon content may be present. However the no noteworthy incre'ase in hard'ness For the production of good bearings naturally it is of paramount importance that the beartary piece and do not separate under the stresses I of. running. Thereisa. difficulty, however, in

the way o'f thisjntimate connection, since the v melting point of the metal which is used for the shells difiers'greatly from that of the suitable alloy. In order to overcome this dim culty it has been proposed that the bearing shells I should be given a. thin coating of copper. This is not, however, in itself sufi'icient to produce the desired effect, care must also be taken to prevent P the accession of air to the parts to be joined to- 0 gether from the time of the, commencement of the necessary warming of the bearing shell up to the termination of the lining process.

This invention overcomes the above difficulty and achieves the desired result by first heating the bearing shell up to a'temperature of about 1050 C. to 1085 0., which has been found to be suitable, in a bath of molten borax and leaving the bearing shell ,"in' such bath for a sufficient r time. By this means not onlyis the shell brought upto the temperature stated-above but also it receives-simultaneously a coating which protects it reliably against oxydation. Before being put into the moltenborax the bearing shell to be lined may be provided with a copper coating f 20 'from 1.5 to 2.5 mm. in thickness.

This invention then provides for the insertion of the prepared bearing shell into a mouldwith a. base of graphite in which it is llned with. the

that the mould with its graphite base should likewise be warmed up before the molten bearing 35 alloy is run in.

After cooling, the completed casting is in the form of a truncated cone, from which the hearing shell can be machined.

.Inthedrawing: ,Fig. .1 a vertical section through a'niould suitab erer-than pose. Fig. 2 is'a'side elevation 0 1 the mould shown inFig. 1.

3 is a. detail view of the base of the mould. Fig. 4 is a detail view of the clamp, and Fig. 5 is a section through Fig. 3 taken on the IineAB. a As shown in the drawing, l is a cast iron'mould with handles 2. The mould hasa conical bore 59 and is provided at its base with an aperture 3 lugs I, intended to cooperate with. the ends or the clamp 5, are provided on the exterior of the mould, approximately at the height of the handles 2; a is the base r the mould which is made 01' 55 originating from the welding. In the meantime an adequate sized crucible containing borax has n secured by tlle two pressing body the crucible and as rapidly as possible,

- undesirable increase with knownbearin been sufliciently heated to render the borax fluid. The shell which preferably has been preheated to C. is submerged ,in the molten borax in left therefor 2 to 3 minutes, after which the shell is'taken out and placed exactly inthe centre of the mould. 0n the upper side of each shell a lug is formed, for example by milling and these lugs are arranged uppermost in the'mould so as .to be engaged by the upper parts of the retaining clamps 5. which embrace the lugs l by their lower ends and thus prevent displacement of the shells during the operation of casting. The introduction of the welded together pair ofbearing shells into the mould must be effected so that the temperature of the bearing does not fall appreciably. As soon as the pair of bearing shells have been clamps 5, a metal alloy of the above mentioned kind, which has in the meantime been melted and deoxydized in the well known manner, by means of phosphor cop-' per,isrunin. Pouring is eifected'in the centre of the shells and such a quantity of molten metal should beused that about 3 overflow 8. This metal which flows out can be caught in a mould-made of dry sand and used for a subsequent cast.

Experience shows that bearings manufactured inthe manner described, in the first 50 hours of running, exhibit a considerable reduction of the lead bronze used as bearing metal, although it is not possible to discover metal particles in the oil can be overcome by the bored-out bushes being compressed by forcing a hard ball or a spherically ground mandrel through the bore. The coin- V is put through the bore of the bearing for the requisite number of times to attain the desired degree of compression.

As a result 'of this compressing step the improved bearing retainsthe amount of clearance which is given to it during manufacture, and the clearance which occurs not take place.

kg. flows out by way of the iIow has found that this disa dvantage' '2,ose,eso

I claim:-

r 1. An improved method for the production of bearings having shells with a lead alloy comprising forming the shells from iron not hardened by heat treatment. then heating said shells in a bath of molten borax up to a temperature of about 1050" C. to 1085 0., then inserting the heated shells into a mould, then casting therein a molten bearing alloy, and then chilling the mould and its contents by plunging into cold water, and finishing the cold bearing to the desired dimensions after removal from the mould.

2. An improved method for the production of bearings having shells with a lining of a copperlead alloy, comprising forming the shells from an alloy of iron containing up to 0.3% carbon, 0.3% silicon and 0.8% manganese; then heating said shells in a bath of 'molten borax perature of about-1050' C. to 1085 C., then inserting the heated shells into a mould, then casting therein a moltembearing alloy, and then chilling the mould and its contents by plunging into cold water, and. finishing the cold bearing to the desired dimensions after removal from the mould; 4 i I p ,3. An improved method for the production of bearings having shells with a lining of a copperlead alloy, comprising forming the shells-from iron not hardened by heat treatment, then heating of said shells in a bath of molten borax up 'to a temperature of about 1050 C. to 1085 C., then inserting theheated shells into a mould, then casting therein a molten bearing alloy, and then chilling the mould and its contents by plunging into cold water, and after removal of the beating from the mould, machining the cold bearing and compressing the .forced passage of a' hardened mandrel through the bore; v 4. An improved method for the'production of bearings having shells with a lining of a copperlead alloy, comprising forming an alloy of iron containing up a 0.3% silicon and 0.6% manganese, then heating said shells in a bath of molten borax up to a temperature of about 1050 C. to 1085 0., then inserting the heated shells into a mould, then casting therein 'a molten bearing alloy, and then chilling the mould and its contents by plunging into cold water, and after removal of the hearing from the mould, machining the cold bearing and compressing the lining metal by'the forced passage of a hardened mandrel through the bore.

Enron snmiLna;

lining of a copper-- up a'temlining metal by the 1 the shells fromto 0.3% carbon.- 

